Pop up advertisements

I need help. I am getting pop up advertisements from the last couple of days. I tried to fix it in many ways. I have Microsoft windows defender installed in my system. I ran Smartfraudfix and also spybot. No use.

I think something got downloaded in my system and invoking these pop-ups. I would like to know what is causing these pop-ups. I tried to find the Dll files created in c/windows/sys32, on the day the problem started. I found a few, but couldnt delete them as it is saying they are in use?

I also noticed that all the pop-ups are coming when ever i do something in the internet explorer.

Hello Suresh, sorry it has taken so long to reply.
Could you please download HiJackThis please then double click and run a full system scan. Save the log and post back here with it and somebody will take a look and determine the next steps to take.